1. Field of the Invention
The present invention relates to a refrigerant compressor and, more particularly, to a refrigerant compressor of which the housing size can be reduced and the configuration of the housing can be designed more freely.
2. Description of the Related Art
A housing in a piston type compressor generally comprises a cylinder block, a front housing connected to the front thereof, and a rear housing connected to the rear thereof. A drive shaft which receives driving power from an external driving source, a cam plate connected to the drive shaft so as to be operated thereby, and pistons connected to the cam plate so as to be operated thereby are arranged in an area extending from the front housing to the cylinder block. In addition, cylinder bores, in which each piston is accommodated so as to be able to reciprocate, are arranged in the cylinder block. Also, a suction chamber into which refrigerant gas sucked into the cylinder bores is introduced and a discharge chamber into which refrigerant gas discharged from the cylinder bores is introduced are arranged in the rear housing.
Moreover, the compressors may further comprise mufflers which damp pulsations transmitted via refrigerant gas to an evaporator and a condenser from the inside of the compressor, check valves which prevent refrigerant gas from flowing reversely, an oil separator which separates a mist of lubrication oil, mixed with refrigerant gas, from the refrigerant gas, a displacement control valve which varies the discharge displacement of the refrigerant gas by changing the stroke of the pistons by pressure control, and so on, as additional components required to increase its function.
As the inside of the cylinder block is occupied by the cylinder bores when the additional components (mufflers, check valves, an oil separator and a displacement control valve) are arranged in the compressor, they are arranged in the front housing or the rear housing.
There is, however, a difficulty in design to provide a space for arranging the additional components because members, such as an arm which attaches the compressor to other members (for example, a vehicle side engine) are located in the front housing and the rear housing. A suction hole and a discharge hole which are communication passages with the outside of the compressor and most of the additional components are concentratedly arranged specially in the rear housing, because the suction chamber and the discharge chamber are closely located around the rear housing. These reasons make the rear housing and, as a result, the compressor, bulky.
The objective of the present invention is to provide a compressor in which the size of a housing thereof can be reduced and also the configuration of the housing can be designed more freely.
In order to solve the above problems, the first aspect of the present invention is a compressor; wherein a crank chamber is formed in a housing, also a drive shaft is supported so as to be able to rotate, cylinder bores are formed in a cylinder block, each piston is accommodated in each cylinder bore so as to be able to reciprocate therein, a cam plate is connected to the drive shaft so as to operate, the pistons are connected to the cam plate so as to operate, and the pistons reciprocate according to the rotation of the drive shaft so that refrigerant gas is sucked and discharged; the cylinder block, which is positioned between the front housing and the rear housing, comprises at least two of a suction space through which refrigerant gas sucked into the cylinder bores passes, a discharge space through which refrigerant gas discharged from the cylinder bores passes, a suction side check valve which is positioned upstream the suction space prevents refrigerant gas introduced into the suction space from reversely flowing upstream the suction space, a discharge side check valve which is positioned downstream the discharge space prevents refrigerant gas discharged from the discharged space to downstream side from reversely flowing into the discharge space, an oil separator which separates a mist of lubrication oil, mixed with refrigerant gas, from the refrigerant gas, and a control valve which varies the pressure in the crank chamber which accommodates the cam plate, between the cylinder bores in the cylinder block.
In this invention, by arranging at least two of the suction space, the discharge space, each check valve, the oil separator, and the control valve between the cylinder bores in the cylinder block, protruding volumes of each of the above-mentioned parts (the suction space, the discharge space, each check valve, the oil separator, and the control valve), outside the housing of the compressor, can be reduced. As the result, the size of the housing can be reduced and also the configuration of the housing (specially for front housing and rear housing) can be designed more freely.
The second aspect of the present invention is that, in the first aspect of the present invention, xe2x80x9cNxe2x80x9d (N is an integral number which is not less than 2) sets of cylinder bores are provided in the cylinder block, and not less than N of the suction space, the discharge space, the suction side check valve, the discharge side check valve, the oil separator, and the control valve are provided between the cylinder bores in the cylinder block.
In this invention, by comprising N sets of cylinder bores in the cylinder block, regions between the same cylinder bores are formed in number xe2x80x9cINxe2x80x9d. By effectively utilizing the N sets of regions, those, not less than N, of the suction space, the discharge space, the suction side check valve, the discharge side check valve, the oil separator, and the control valve are disposed in the regions so that the size of the housing can be more preferably reduced and also the configuration of the housing can be designed more freely.
The third aspect of the present invention is that, in the second aspect of the present invention, at least one of the suction space, the discharge space, the suction side check valve, the discharge side check valve, the oil separator, and the control valve are provided between each cylinder bore in the cylinder block.
In this invention, all of the regions between the cylinder bores are utilized for disposing at least one of the suction space, the discharge space, the suction side check valve, the discharge side check valve, the oil separator, and the control valve therein. That is to say, all of the regions between the cylinder bores are utilized for such disposition. This allows that the size of the housing can be more preferably reduced and also the configuration of the housing can be designed more freely.
The fourth aspect of the present invention is that, in any one of the first aspect to third aspect of the present invention, at least one of the suction space or the discharge space are provided between the cylinder bores in the cylinder block.
In this invention, the suction space and the discharge space, which require relatively large space, are disposed in the cylinder block, so that the size of the compressor can be effectively reduced and also the configuration of the housing can be designed more freely.
The fifth aspect of the present invention is that, in any one of the second aspect to fourth aspect of the present invention, the discharge space is provided between the cylinder bores in the cylinder block and at least one of the discharge side check valve or the oil separator are disposed in the discharge space.
In this invention, the discharge space is utilized to dispose at least one of the discharge side check valve or the oil separator therein so that the regions between the cylinder bores are utilized more effectively. Thus the size of the housing can be more preferably reduced and also the configuration of the housing can be designed more freely.
The sixth aspect of the present invention is that, in any one of the first aspect to fifth aspect of the present invention, the pressure difference, through the piston, between the pressure in the crank chamber and the pressure in the cylinder bores is varied by the control valve, and then the inclination angle of the cam plate is changed according to the pressure difference, so that the compressor is a variable displacement type which controls the discharge displacement thereof.
In this invention, the compressor is constructed as a variable displacement type and a control valve having a relatively large volume is added to the optional components which are disposed between cylinder bores in the cylinder block so that the size of the housing of the compressor of variable displacement type can be more effectively reduced and also the configuration of the housing can be designed more freely.
The seventh aspect of the present invention is that, in the sixth aspect of the present invention, cylinder bores, which number not less than three, are provided in the cylinder block and the suction space, the discharge space and the control valve are provided between the cylinder bores in the cylinder block.
In this invention, the suction space, the discharge space and the control valve which require a relatively large space are disposed between the cylinder bores 1a in the cylinder block, so that the size of the compressor can be effectively reduced and also the configuration of the housing can be designed more freely.
The present invention may be more fully understood from the description of the preferred embodiments of the invention set forth below, together with the accompanying drawings.